Pre-commit is a great tool for running various sanity checks (formatting, linting) on the code base. However, such scanning may be time-consuming (particularly on certain content like notebooks) which hits both user experience and billing for CI/CD (minutes are usually paid, except for public repos or very small projects).
Below, I demonstrate how to effectively optimize running pre-commit on GitHub Actions. The key is to cache both the pre-commit package and dependent hooks. Note that, as of now (April 2023), pre-commit native caching does only the second part. Fortunately, managing its cache is as simple as calling the GitHub Cache Action on ~/.cache/pre-commit.
name: pre-commit
on:
push:
branches: [experiments]
pull_request:
branches: [experiments, main]
workflow_dispatch:
jobs:
pre-commit:
runs-on: ubuntu-latest
steps:
- uses: actions/checkout@v3
- uses: actions/setup-python@v4
with:
python-version: 3.7
- name: cache pre-commit deps
id: cache_pre_commit
uses: actions/cache@v3
env:
cache-name: cache-pre-commit
with:
path: |
.pre_commit_venv
~/.cache/pre-commit
key: ${{ env.cache-name }}-${{ hashFiles('.pre-commit-config.yaml','~/.cache/pre-commit/*') }}
- name: install pre-commit
if: steps.cache_pre_commit.outputs.cache-hit != 'true'
run: |
python -m venv .pre_commit_venv
. .pre_commit_venv/bin/activate
pip install --upgrade pip
pip install pre-commit
pre-commit install --install-hooks
pre-commit gc
- name: run pre-commit hooks
run: |
. .pre_commit_venv/bin/activate
pre-commit run --color=always --all-files